Holder for interchangeably supporting knives against the periphery of revolving drums



Jan. 4, 1955 G. L. GARRow 2,698,453

HOLDER FOR INTERCHANGEABLY SUPPORTING KNIVES AGAINST THE PERIPHERY OF' REVOLVING DRUMS Filed Sept. l1, 1952 4 Sheets-Sheet l 42 W/' O 0 0 5,33 ogoo o gygy@ Jan. 4, 1955 G, @ARROW 2,698,453 f HOLDER FOR INTERCHANGEABLY SUPPORTING KNIVES AGAINST THE PERIPHERY 0F REVOLVING DRUMS Filed Sept. 11, 1952 4 Sheets-Sheet 2 IN V EN TOR.

Jan. 4, T955, G l. GARRow 2,698,453

HOLDR FOR INTER'CHANGEABLY SUPPORTING KNIVES AGAINST THE PERIPHERY OF REVOLVING DRUMS Filed Sept. ll, 1952 4 Sheets-Sheet 3 1 l l r IN VEN TOR.

Jan. 4, 1955 G. L. GARRo 2,698,453

HOLDER FOR TERCHANGEA S ORTING KNIVES PERI? AGAINST HERY REVOLVING DRUMS Y Filed Septfll, 1952 4 Sheets-Sheet 4 United States Patent Oice 2,698,453 Patented Jan. 4, 1955 HOLDER FOR INTERCHANGEABLY SUPPORTING KNIVES AGAINST THE PERIPHERY OF` RE- VGLVING DRUMS Gerard L. Garrow, Cheektowaga, N. Y., assignor, by

mesne g assignments, to Blaw-Knox Company, Pittsburgh, Pa., a corporation of Delaware Application September 11, 1952, Serial No. 309,037

12 Claims. (Cl. 15256.5)

This invention relates to a holder for a plurality of knives adapted to be nterchanged in the removal of lthe product film from a revolving drum surface and particularly from the drums of drum dryers or llakers where a liquid or semi-liquid film is applied to a revolving drum surface for the purpose of drying and removing moisture or hardening the film and where the dry product llm is continually removed before a full revolution of the drum has been completed. In such a drum dryer or flaker the continuous removal of the dried or hardened product fllm and the continuous application of a liquid or semiliquid to the drum surface following the removal of the dry or hardened product film makes the drying process continuous.

The principal object of the present invention is to provide, in conjunction with a drum dryer or llaker, a holder for more than one knife in which the knives can be readily exchanged in operation and the free knife readily adjusted or removed and sharpened and honed while the drum dryer or flaker is in operation with the companion knife. By this means the time during which the dryer or aker has to be shut down for knife changes and maintenance is greatly reduced.

Another object of the invention is to facilitate the removal and resharpening and honing of the knives both to reduce power consumption and danger of damage to the drum and also to improve the product. At present knives frequently are used for too long a period which causes them to become dull and often results in damage to the drum if they are nicked. By facilitating the removal of the knife, and the exchange of a fresh knife, knife change is facilitated thereby to eliminate thepower lost by running with dull knives and also greatly reducing risk of damage to the drum. In addition, by readily maintaining the knives in lirst class condition, the drums are cleaned more completely and also the quality of material removed is improved because it no longer becomes contaminated by material which otherwise adheres to the drum for more than one revolution and which may become overheated or scorched.

Another object of the invention is to provide such a multiple knife holder in which the inoperative knife does not interfere with the functioning of the operative knife or other parts of the dryer or flaker and at the same time is immediately available for exchange.

Another object of the invention is to provide such a multiple knife holder which can be applied to any type of revolving drum whether single or double or heated or cooled.

Another object of the invention is to provide such a knife holder which is not liable to become contaminated with the product film and which can be readily kept in a clean and sanitary condition.

Another object is to provide such a multiple knife holder which is low in cost and rugged and durable in construction so as to stand up under conditionsof severe and constant use.

Other objects and advantages of the invention will be apparrlent from the following description and drawings in whic Fig. l is a vertical transverse section through a single drum dryer or flaker equipped with a multiple knife holder embodying the present invention.

Fig. 2 is an enlarged horizontal section taken generally on line 2--2, Fig. 1.

Fig. 3 is a further enlarged vertical transverse section taken generally online 3--3, Fig. 2.

Fig. 4 is an enlarged fragmentary section taken generally on line 4-4, Fig. 2.

Fig. 5 is an enlarged vertical transverse section taken on line 5 5, Fig. 2.

Fig. 6 is a view similar to Fig. 1 and illustrating a modifcation of the invention particularly applicable to double drum dryers.

Fig. 7 is a fragmentary side elevational view, viewed from the right of Fig. 6.

Figs. 8, 9, 10 and 11 are enlarged fragmentary sectional views taken on the correspondingly numbered lines of Fig. 7

Fig. 12 is a sectional view taken online 12-12, Fig. 9.

The invention as illustrated in Figs. 1-5 is shown in conjunction with a drum dryer or aker which is of the single drum type and which is conventionally shown as having the usual end heads or standards 10 in which the opposite ends of a drum 11 are joumalled by bearings indicated at 12. This drum 11 can be internally heated in any suitable manner so as to remove moisture from a liquid or semi-liquid iilm applied to its periphery. This drum can also be internally cooled to harden a film of liquid or semi-liquid material applied to its periphery. In either case the liquid or semi-liquid material is applied to the surface of the drum at a point remote from the knife holder embodying the present invention and the drum is rotated in a direction, indicated by the arrows in Figs. 1 and 3, to bring the hardened or dried product lm into engagement with the operative knife carried by the knife holder.

The knife holder of the present invention is designed to carry two knives 15 one of which is maintained in operative contact with the periphery of the drum 11 and the other of which is in standby service and available for ready exchange with the operative knife when the operative knife becomes dull or when an adjustment of the operative knife is indicated. Each of the knives 15 preferably extends the full axial length of the drum 11 and has a beveled sharp edge 16 which is adapted to be brought into contact with the surface of the drum 11 in the manner shown in Fig. 3.

The knife holder is shown as including a rotatable tubular support 17 having a pair of parallel metal channel bars 18 which are arranged with their flanges 19 opposing one another. Each pair of these flanges 19 are ioined bv a metal side plate 20 which extends the full length of the channel bars 18 and these side plates are welded to the flanges 19 so as to form an elongated tubular support which is generallv square in cross-section as illustrated in Fig. 3. The ends of this tubular shaft structure are preferablv each enclosed by a souare end plate 21 which can be welded in place and each of these end plates has fixed thereto a stub shaft or trunnion 23. These stnh hatte mfwrmions nfoieet co-axiallv and are shown as journalled in bearings 24 mounted on suitable bearing brackets 25 carried bv the end stands 10 of the drver.

A feature of the invention resides in the positioning of the rotatable tubular support composed of the channels 18 and side plates 20 with the side plates 20 vertical either in the position shown in Fig. 3 or rotated l80 in the bearings 24. To hold this structure in either of these two positions one or both of the end bearings 24 is provided in its top with a radial hole 26 adapted to receive a manuallv removable pin 28 the inner end of which can enter either of two opposite radial bores 29 provided in the corresponding trunnion l23. These pins hold the rotatable structure 17 against rotation in. say, the position shown in Fig. 3, and when a knife change is required these pins can be removed. the rotatable structure 17 rotated in the bearings 24 180I and the pins 28 reinserted in the bores 29 on the opposite sides of the trunnions 23.

In order to facilitate such turning of the rotatable tubular structure 17, as well as the removal and insertion of the pins 28, the rotatable tubular structure 17 is preferably provided with handles 30. One of such handles is preferably provided at each end of each channel bar 18 and can be in the form, as shown, of a U-shaped grip with its legs welded to the corresponding end of each channel bar 18 and with the grip extending lengthwise of the channel bar.

To each of the side plates 20 of the rotatable structure 17 is pivotally secured a. holder 31 for the corresponding knife blade 15. Each of these holders comprises a backing frame or plate 32 of conventional form and shown as a casting extending the full length of the drum 11. This backing plate is provided with a plurality of integral knuckles 33 which are fast to a shaft 34 the opposite ends of which extend beyond the backing plate or frame 32 and beyond the ends of the drum 11. To mount the knife blade on each backing plate or frame 32, each backing plate or frame is recessed its full length on the side remote from its knuckles 33 to provide a face 35, which extends radially relative to the axis of the shaft 34, and also to provide a shoulder 36. Each knife blade 15 is placed against the face 35 and is clamped thereto by a clamping plate 38 by means of screws 39 anchored in the backing plate or frame 32 and drawing this clamping plate 38 into clamping engagement with one face of the knife blade. Preferably the inner edge of each of these clamping plates 38 abuts the shoulder 36.

Each shaft 34 is suitably journalled in a bearing bracket 40, these bearing brackets being secured in any suitable manner to the corresponding side plate of the rotatable tubular structure 17. Preferably each of these bearing brackets 40 is arranged immediately adjacent a corresponding knuckle 33 to the knife holder 31.

To permit of manually swinging each knife holder 31 into and out of operative position each end of each of the shafts 34 is provided with a radial handle preferably in the form of a hub 41 fast to the corresponding end of each shaft 34 and having a radially extending rod 42. Preferably these rods are located beyond the ends of the drum 11 and beyond the ends of the knife holders 31 so that they can be made of the length shown and at the same time be rotated 360 without interference with the drum or knife holders,

Fast to each of the shafts 34 adjacent each knuckle 33 of each knife holder 31 is a crank arm 43. The outer end of each of these crank arms carries a crank piu 44 which is arranged parallel with the shaft 34. Each of these crank pins is adapted to be removably secured to an adjustable link indicated generally at 45. As best shown in Figs. 3 and 4 each of these adjustable links 45 is preferably in the form of a metal head 46 having a notch 48 in one side adapted to be placed over the corresponding crank pin 44. ln this metal head is journalled, in any suitable manner, an adjusting rod 49 which is permitted to turn relative to the head 46 but held against relative longitudinal movement by any convventional form of retainer 50. The opposite end of each adjusting rod 49 is threaded, as indicated at 51, and its extreme outer end is provided with a souared head 52 so that a wrench can be applied to the adjusting rod in effecting adjustment.

The threaded part 51 of each rod 49 screws into a nut 53 which is preferably in the form of a cylinder with its axis arranged at right angles to the axis of the adjusting rod 49 and having its ends journalled in a pair of ears 54 of a bracket 55. Each of these brackets is secured in any suitable manner to the outer face of the corresponding channel bar 18.

In the use of the apparatus, the operator rotates, by means of the handles 30, the rotatable tubular structure 17, to, say. the position shown in Fig. 3, and then inserts the pins 28 through the holes 26 in the bearings 24 and into the corresponding radial bores 29 in the trunnions 23 of this rotatable structure. He then seizes one of the handles or rods 42 associated with that knife blade 15 closest to the drum 11 and swings it from the dotted line position shown in Fig. 3 to the full line position shown in this figure. This swings the sharpened edge of the corresponding knife blade 15 into close proximity with the periphery of the drum 11, the handle 42 rotating the corresponding shaft 34 in the bearing brackets 40 and swinging the knife holder 31 secured to this shaft through its knuckles 33 so as to move the knife blade 15 into close proximity with the drum.

The operator then swings the extensible links 45 about the axis of their nuts 53 journalled in the bearing brackets 55 so as to cause the notches 48 in the heads 46 of these extensible links to receive the crank pins 44 on the crank arms 43. Since these crank arms 43 are faSt t9 ih@ shaft 34 it will be seen that these adjustable links hold the knife blade 15 in close proximity to the periphery of the drum 11.

The operator then applies a wrench to the square ends of the adjusting rods 49 associated with the knife being readied. Since these adjusting rods have threaded engagement with the nuts 53, turning these adjusting rods causes these rods to move longitudinally and these roos, in adjusting the knife, are turned in a direction to draw their heads 46 outwardly thereby to rotate the crank arms 43 and shaft 34 in that direction to cause the knife holder 31 to move the sharpened edge of the knife 15 into firm contact with the periphery of the drum. After each adjusting rod 49 has been turned to the extent required to effect the desired pressure between its sharpened edge 16 of the corresponding knife blade 15 against the periphery of the drum the drying operation is started.

When the sharpened edge 16 of the knife blade 15 in operation becomes worn to an extent to make resharpening desirable the operator stops the operation of the drum 11 for the brief period required for a knife change with the present apparatus. This knife change involves applying a wrench to the square end 50 of each of the adjusting screws 49 so as to relieve the knife contact pressure of the adjustable links 45 against the crank arms 43. This also permits the shaft 34 to swing in a direction to permit the corresponding knife holder 31 to drop by gravity and to disengage the sharpened edge 16 of its knife 15 from the periphery of the drum. The operator then lifts the heads 46 of the adjustable links 45 so as to free the crank pins 44 from the notches 48 in these heads. This completely releases that knife holder 31 toward the drum 11 and permits it to swing down to the dotted line position shown at the left of Fig. 3. The fall of the knife holder is, of course, controlled by the operator through one of the handes 42 associated with this knife holder.

LThe operator then pulls the two pins 2S which permits the rotatable tubular structure 17 to be rotated in the bearings 24. Through the handles 30 the operator rotates this rotatable tubular structure and reinserts the pins 28 through the holes 26 in the bearings 24 into the alining bores 29 in the trunnions 23.

By this rotation the other knife holder 31, formerly at the right hand side of Fig. 3, is swung into proximity with the drum 11 and the knife of this knife holder is then adjusted to engage the periphery of the drum 11 in the same manner as first described. Thus, the operator seizes one of the handles 42 and, through the shaft 34 and knuckles 33 swings the knife holder 3l upwardly so as to present the sharpened edge 16 of its knife 15 to the periphery of the drum 11 and suflicientlv far so that the notches 48 in the heads 46 of the ad justable links 45 can be engaged with the crank pins 44 of the cranks 43 fast to the shaft 34. By means of a wrench applied to the squared ends 52 of the threaded adjusting rods 49, these rods are then turned to draw the heads 46 outwardly and, through the crank arms 43, shaft 34 and knuckles 33 of the knife holders 31 to bring the sharpened edge 16 of the corresponding7 knife blade 15 into firm engagement with the periphery of the drum.

The operator then again starts the drying operation and while the drying operation is proceeding lic can leisurely remove the knife blade 15 of the now inoperative knife holder 31. This is done by loosening of the screws 39 which relieves the clamping pressure of the clamping plate 3S against the now inoperative knife blade 15; The knife blade is then removed, resharpened, honed and replaced so as to be conveniently available when another knife change is desirable.

The modified form of the invention illustrated in Figs. 6-12 is shown in conjunction with a double drum dryer conventionally shown as having the usual end heads or standards 60 in which the opposite ends of a pair of parallel, closely spaced drums 61 are journalled by bearings indicated at 62. The drums 61 can be heated or cooled in the usual manner to remove moisture from or to harden a liquid or semi-liquid layer applied to their peripherie's. In either case the liquid or semiliquid is fed into the valley between the drums to build up as a body therein, and a film is picked up by each drum and carried downwardly through the space along the line of closest approach of the drums, and under the undersides of the drums and up the rising sides thereof near the top of which rising sides the dried or hardened layer is removed by the knives carried by the knife holders forming the subject of the present invention.

As with the form of the invention shown in Figs. 1-5, each knife holder is designed to carry two knives one of which is maintained in operative contact with the periphery of the corresponding drum 61 and the other of which is in standby service and available for ready exchange with the operative knife when the operative knife becomes dull. Each of the knives preferably extends the full axial length of the corresponding drum 61 and has a beveled sharp edge 66 which is adapted to be brought into contact with the surface of its drum 61 in the manner shown in Fig. 8.

The knife holder is shown as including a rotatable tubular support 67 having a pair of parallel metal channel bars 68 which are arranged with their flanges 69 opposing one another. Each pair of these flanges 69 are joined by metal side plate 70 which extends the full length of the channel bars 68 and these side plates are welded to the anges 69 so as to form an elongated tubular support which is generally square in cross section as illustrated in Fig. 8. The ends of this tubular shaft structure are preferably each enclosed by a square end plate 71 which can be welded in place and each of these end plates has xed thereto a stub shaft or trunnion 73. These stub shafts or trunnions project coaxially and are shown as journalled in bearings contained in bearing brackets 75 carried by the end stands 60 of the dryer.

A feature of the invention resides in the positioning of the rotatable tubular support composed of the channels l 68 and side plates 70 with the side plates horizontal either in the position shown in Figs. 6 and 8 or rotated 180 in the bearings 75. To hold this structure in either of these two positions and also to provide adjustment of the pressure of the operative knife 65, each stub shaft or trunnion 73 is provided with a ypair of opposite radial bores 78 the open ends of which are embraced by the hub 79 of an adjusting lever 80. Each hub is operatively connected with its stub shaft or extension 73, as best shown in Fig. 10, by a T-headed pin 81 which extends through a radial hole 82 in the hub and into the corresponding bore 78 in the stub shaft or extension 73.

The lower end of the adjusting lever carries a cross pin 83 which forms a pivot between this lever and a U-shaped yoke 84 the arms 85 of which straddle the end of the adjusting lever 80 and connect with the pivot pin 83. The cross part 86 of the U-shaped yoke 85 is held in an annular external groove 88 of the head 89 of a horizontal adjusting screw 90. This screw works in a nut 91 horizontally swivelled in the corresponding end stand 60 and has a hand wheel 92 fast thereto.

To facilitate the turning of the tubular rotatable support 67 to its opposite 180 positions determined by the pins 81 in the radial bores 78 of the stub shafts 73 of the support, as well as to facilitate insertion of these pins, this rotatable tubular support is preferably provided with handles 93. These handles can be 1n the form of rods removably insertable into any one of an annular series of radial bores 94 provided in each stub shaft 73 as best shown in Figs. 7 and 8.

To each of the side plates 70 of the tubular rotatable structure 67 is pivotally secured a holder 95 for the corresponding knife blade 65. Each of these holders comprises a tube 96 in which is inserted a rod 98, this rod being welded to the tube and having its ends 99, 100 projecting therefrom. To one side of each tube is welded the edge of a backing plate 101, this plate extending the full length of its tube 96 and projecting laterally tangentially therefrom. On the side of each t backing plate 101 opposing the tube 96 is arranged the corresponding knife blade 65 and this blade is clamped in position by a clamping plate 102 through clamping screws 103 which extend at spaced intervals through each clamping plate 102 and anchor in the corresponding backing plate 101.

The projecting ends 99, 100 of the shaft 98 of each knife holder are respectively journalled in a pair of bearings 104, 105 fast to opposite ends of the corresponding side plate 70. The projecting end 100 is provided with a pair of keyways 107, 108 each of these keyways extending axially inwardly from the extremity of its shaft end 100. Each of these keyways is arranged to mate with a companion keyway 109 provided in the bearing 105. In the mated position of the keyway 109 with either of the keyways 107, 108 it can receive a key 110. This key 110 preferably has a loose fit in the keyway jointly provided by the keyway 109 with either of the keyways 107 or 108 and this key is preferably provided with a T-head to facilitate its insertion and removal.

To facilitate rotation of either of the knife holders 95 as well as to facilitate insertion of the key 110, the projecting end 100 of the shaft 98 is provided with an annular series of radial bores 111. A rod 112 can be removably inserted in any one of these radial bores 111.

j In describing the use of the device for a double drum dryer or aker as shown in Figs. 1-12, it will be assumed that a sharp knife 65 is in standby service at the top of the holder for one of the drums 61 and that the other knife 65 in contact with the periphery of this drum 61 has become dull.

The operator first inserts a rod 93 in one of the radial holes 94 in the stub shaft 73 so as to have control of the rotation of the rotatable tubular support 67. I-Ie then turns the two hand wheels 92 so as to back the screws along the nuts 91 or to the right as illustrated in Fig. 10. Through the yoke and pivot pin 83 this swings the adjusting levers 80 counterclockwise as viewed in Fig. 10 thereby, through the pin 81, to move the rotatable tubular structure 67 also counterclockwise as viewed in Figs. 6 and 8. Accordingly the sharp edge 66 of the lower or operative knife 65 is moved away from the periphery of its drum 61.

The operator then removes the two pins 81 thereby to permit free rotation of the rotatable tubular structure 67 in its bearings 75. By the handle provided by the rod 93 in one of the bores 94 the operator then swings the rotatable tubular structure 67 counterclockwise as viewed in Figs. 6 and 8. He then inserts the smaller rod 112 in one of the bores 111 of the projecting end of the shaft 98 of the holder for the worn knife 65 so as to have control of the rotation of this holder. The operator then removes the key from the axially extending keyways 108, 109, thereby to free the holder 95 for the worn knife. This holder 95 for the worn knife drops, under control of the rod or handle 112, to a pendent position in which its worn knife 65 is vertical and projects downwardly. In this position the keyway 107 is brought into register with the keyway 109 and the key 110 is reinserted in the registering keyways 107 and 109.

The operator then swings the rod 93 so as to rotate the rotatable support 67 clockwise 180 which brings the 5 holder for the sharp knife 65 to the position which was previously occupied by the dull knife. That is, it is in a pendent position in front of the rotatable holder 67. The operator then removes the key 110 from the keyways 107, 109 of the so positioned holder for the sharp knife and lifts the knife holder contained in the sharp knife until the keys 108, 109 come into registry, He thereupon reinserts the key 110 in the registering keyways 108 and 109.

The operator then, through the handle or rod 93, swings the rotatable holder 67 clockwise until the edge 66 of the sharpened knife is brought into contact with the periphery of the drums 61 and also inserts the pin 81 (Fig. 10) in the uppermost radial bore 78 of the stub shaft 73. This locks the rotatable holder 67 against rotation relative to the adjusting arm 80.

The operator then turns the hand wheels 92 of the adjusting screws 90, these screws moving axially in the nuts 91 so as to adjust the adjusting levers 80 in a horizontal direction to the left as viewed in Fig. 10. Since the rotatable supporting structure 67 is now pinned to these adjusting levers 80 through the pins 81, this adjustment of these hand wheels 92 serves to provide the desired contact pressure between the sharpened edge 66 of the fresh knife 65 and the periphery of the drum 61.

The dull knife is now in the uppermost position shown in Figs. 6 and 8 and while the product film is being removed from the drum by the sharp knife, the screws 103 of the upper dull knife 65 can readily be loosened thereby to permit this dull knife to be withdrawn horizontally,

resharpened and replaced for standby service and for a repetation of the replacement cycle as above described.

From the foregoing it will be seen that the present invention provides a very simple holder for a plurality of knives which permits them to be quickly and easily interchanged in service so that knife change involves a minimum shutdown of the drying operation and minimum effort and time. It will further be seen that both forms of the holder are very simple and inexpensive in construction and that the inoperative knife can readily be removed, reconditioned and replaced.

I claim:

l. A holder for interchangeably supporting a plurality of knives adapted to remove the product film from the periphery of a revolving drum, comprising a rotatable support adapted to be mounted adjacent the periphery of said drum to rotate about an axis parallel with the axis of said drum, a plurality of knife backing plates pivoted to different sides of said rotatable support to swing about axes parallel with the axis of said rotatable support, a

knives and in each of which positions a corresponding knife backing plate is in position to have the edge of its knife brought into Contact with the periphery of said drum, and means operatively interposed between each knife backing plate and said rotatable support and arranged to hold the edge of each knife in contact with the periphery of said drum.

2. A holder for interchangeably supporting a plurality of knives adapted to remove the product film from the periphery of a revolving drum, comprising a rotatable support adapted to be mounted adjacent the periphery of said drum to rotate about an axis parallel with the axis of said drum, a plurality of knife backing plates pivoted to different sides of said rotatable support to swing about axes parallel with the axis of said rotatable support, a knife removably mounted on each of said backing plates in position to engage its edge with the periphery of said drum, a first holding means arranged to hold said rotatable support in positions of rotation corresponding to the number of knives and in each of which positions a corresponding knife backing plate is in position to have the edge of its knife brought into contact with the periphery of said drum and a second holding means operatively interposed between each knife backing plate and said rotatable support adapted to be and arranged to hold the knife backing in a position in which the edge of its knife is in contact with the periphery of said drum, one of said holding means including a mechanism for adjusting the pressure of said knives against said drum.

3. A holder for interchangeably supporting a plurality of knives adapted to remove the product film from the periphery of a revolving drum, comprising a rotatable support adapted to be mounted adjacent the periphery of said drum to rotate about an axis parallel with the axis of said drum, a plurality of knife backing plates pivoted to different sides of said rotatable support to swing about axes parallel with the axis of said rotatable support, a knife removably mounted on each of said backing plates in position to engage its edge with the periphery of said drum, means arranged to hold said rotatable support in positions of rotation corresponding to the number of said knives and in each of which positions a corresponding knife backing plate is in position to have the edge of its knife brought into contact with the periphery of said drum, and adjustable means operatively interposed between each knife backing plate and said rotatable support and arranged to draw and hold the edge of each knife in contact with the periphery of said drum, comprising a crank arm fast to each knife backing plate, and a manually extensible link connecting the free end of each crank arm with said rotatable support.

4. A holder for interchangeably supporting a plurality of knives adapted to remove the product film from the periphery of a revolving drum, comprising a rotatable support adapted to be mounted adjacent the periphery of said drum to rotate about an axis parallel with the axis of said drum, a plurality of knife backing plates pivoted to different sides of said rotatable support to swing about axes parallel with the axis of said rotatable support, a knife removably mounted on each of said backing plates in position to engage its edge with the periphery of said drum, means arranged to lock said rotatable support in positions of rotation corresponding to the number of said knives and in each of which positions a corresponding knife backing plate is iu position to have the edge of its knife brought into contact with the periphery of said drum, and adjustable means operatively interposed between each knife backing plate and said rotatable support and arranged to draw and hold the edge of each knife in Contact with the periphery of said drum, comprising a crank arm fast to each knife backing plate, a crank pin at the free end of each crank arm and arranged parallel with the axis of its knife backing plate, a rod associated with each crank arm, a head mounted on each rod and having a notch in one side arranged to engage over the corresponding crank pin, and means adjustably securing each rod to said rotatable support and permitting longitudinal adjustment of said rod.

5. A holder for interchangeably supporting a plurality of knives adapted to remove the product film from the periphery of a revolving drum, comprising a rotatable support adapted to be mounted adjacent the periphery of said drum to rotate about an axis parallel with the axis of said drum, a plurality of knife backing plates pivoted to dierent sides of said rotatable support to swing about axes parallel with the axis of said rotatable support, a knife removably mounted on each of said backing plates in position to engage its edge with the periphery of said drum, means arranged to lock said rotatable support in positions of rotation corresponding to the number of said knives and in each of which positions a corresponding knife backing plate is in position to have the edge of its knife brought into contact with the periphery of said drum, and adjustable means operatively interposed between each knife backing plate and said rotatable support and arranged to draw and hold the edge of each knife in contact with the periphery of said drum, comprising a crank arm fast to each back plate, a crank pin at the free end of each crank arm and arranged parallel with the axis of its knife backing plate, a head associated with each crank arm and having a notch in one side arranged to engage over the corresponding crank pin, a rod having one end threaded and its other end rotatably secured to said head, and a nut fitting said threaded end of said rod and rotatably secured on said rotatable support to swing about an axis parallel with the axisof said rotatable support.

6. A holder for interchangeably supporting a plurality of knives adapted to remove the product film from the periphery of a revolving drum, comprising a rotatable support adapted to be mounted adjacent the periphery of said drum to rotate about an axis parallel with the axis of said drum, a plurality of knife backing plates pivoted to different sides of said rotatable support to swing about axes parallel with the axis of said rotatable support, a knife removably mounted on each of said backing plates in position to engage its edge with the periphery of said drum, means arranged to lock said rotatable support in positions of rotation corresponding to the number of said knives and in each of which positions a corresponding knife backing plate is in position to have the edge of its knife brought into contact with the periphery of said drum, and quick detachable adjustable means operatively interposed between each knife backing plate and said rotatable support and arranged to draw and hold the edge of each knife in contact with the periphery of said drum.

7. A holder for interchangeably supporting a plurality of knives adapted to remove the product film from the periphery of a revolving drum, comprising a rotatable support adapted to be mounted adjacent the periphery of said drum to rotate about an axis parallel with the axis of said drum, a plurality of knife backing plates pivoted to different sides of said rotatable support to swing about axes parallel with the axis of said rotatable support, a knife removably mounted on each of said backing plates in position to engage its edge with the periphery of said drum, means arranged to lock said rotatable support in positions of rotation corresponding to the number of said knives and in each of which positions a corresponding knife backing plate is in position to have the edge of its knife brought into contact with the periphery of said drum, quick detachable adjustable means operatively interposed between each knife backing plate and said rotatable support and arranged to draw and hold the edge of each knife in contact with the periphery of said drum, and a hand lever fast to each of said knife backing plates to facilitate manipulation thereo 8. A holder for interchangeably supporting a plurality of knives adapted to remove the product film from the periphery of a revolving drum, comprising a rotatable support adapted to be mounted adjacent the periphery of said drum to rotate about an axis parallel with the axis of said drum, a plurality of shafts journalled on different sides of said rotatable support to swing about an axis parallel with the axis of said rotatable support, a knife backing plate fast to each of said shafts, a knife removably mounted on each of said backing plates in position to engage its edge with the periphery of said drum, means arranged to lock said rotatable support in positions of rotation corresponding to the number of said knives and in each of which positions a corresponding knife backing plate is in position to have the edge of its knife brought into contact with the periphery of said drum, a crank arm fast to each shaft, a rod detachably connected to each of said crank arms, and means anchoring said rod on said rotatable support in different positions of longitudinal adjustment of said rod on said rotatable support.

9. A holder for interchangeably supporting a plurality of knives adapted to remove the product film from the periphery of a revolving drum, comprising a rotatable support adapted to be mounted adjacent the periphery of said drum to rotate about an axis parallel with the axis of said drum, a plurality of shafts journalled on different sides of said rotatable support to swing about an axis parallel with the axis of said rotatable support, a knife backing plate fast to each of said shafts, a knife removably mounted on each of said backing plates in position to engage its edge with the periphery of said drum, means arranged to lock said rotatable support in positions of rotation corresponding to the number of said knives and in each of which positions a corresponding knife backing plate is in position to have the edge of its knife brought into contact with the periphery of said drum, a crank arm fast to each shaft, a rod detachably connected to each of said crank arms, means anchoring said rod on said rotatable support in different positions f longitudinal adjustment of said rod on said rotatable support and a hand lever fast to each of said shafts to facilitate manipulation of said knife backing plates.

l0. In combination with a revolving drum journalled in stationary end stands, a holder for interchangeably supporting a plurality of knives adapted to remove the product film from the periphery of said drum, comprising a rotatable support which is generally rectangular in cross section, coaxial trunnions at the opposite ends of said support and journalled in bearings on said end stands, a pair of bearing brackets secured to each of a rst two opposite faces of said rotatable support on an axis arranged parallel with the axis of said rotatable support, a shaft journalled in each pair of said bearing brackets, a knife backing plate secured at one edge to each of said shafts to oscillate therewith, a knife removably mounted on each of said backing plates to project from the opposite edge thereof, means carried by one of said ends stands and arranged to lock said rotatable support in two positions of rotation and in each of which positions a corresponding knife backing plate is in position to have the edge of its knife brought into contact with the periphery of said drum, a crank arrn fast to each of said shafts, a head detachably connected to each of said crank arms, an adjusting rod rotatably secured to each head and having its opposite end threaded, a nut on the threaded end of each adjusting rod, and a bracket securing each nut to the second two opposite faces of said rotatable support.

1l. A structure as set forth in claim 2 wherein said first holding means includes said mechanism for adjusting the pressure against said drum and comprises a coaxial shaft fast to said rotatable support, an adjusting lever having its hub journalled on said shaft, a removable pin connecting said hub and shaft in different positions of relative rotation, and means for adjusting the position of said lever with reference to a stationary part.

12. A structure as set forth in claim 2 wherein said second holding means includes a shaft fast to each knife backing plate and disposed parallel with the edge of said knife, a bearing on said rotatable support in which said shaft is journalled, said shaft and bearing being provided with axial keyways arranged to register with each other, and a key loosely fitted in said registering keyways.

References Cited in the file of this patent UNITED STATES PATENTS 1,650,758 Kukla Nov. 29, 1927 l,884,727 Kermer Oct. 2.5, 1932 2,209,257 Blank July 23, 1940 FOREIGN PATENTS 74,364 Austria Mar. 15, 1917 

